Machine for finishing or grinding arcuate surfaces



1948 J. VAN BUREN 3 MACHINE FOR FINISHING OR GRINDING ARCUATE SURFACESNew 4 Sheets-Sheet 1 Filed Nov. 24, 1945 R om n T N NP R w m N T I A QRmm J. VAN BUREN NM? 8, 1949 2,47,2m1 MACHINE FORFINISHING OR GRINDIINGARCUATE SURFACES 4 SheetsSheet 2 Filed NOV. 24, 1945 llll O 0 Q8 QwIINVENTOR Hues/v Joy/v l A/V ATTORNEY Ngv. 2949 J. VAN BUREN 7 MACHINEFOR FINISHING 0R GRINDING ARCUATE SURFACES Filed Nov. 24, 1945 4Sheets-Sheet s O 60 58 S INVENTOR l l JOHN VAN Bun/51v BY //0 A ATTORNEYNW. 8, 394 J. VAN BUREN MACHINE FOR FINISHING OR GRINDING ARCUATESURFACES 4 Sheets-Sheet 4 Filed NOV. 24, 1945 INVENTQR BURL Jaw/v VA/VPatented Nov. 8, 1949 orrice MACHINE FOR FINISHING OR GRINDING ARCUATESURFACES John Van Buren, Brooklyn, N. Y. 7 Application November 24,1945, Serial N0. 630,651

'2 Claims. (c1. 51 101)' This invention relates ing or grinding arcuatesurfaces.

. The invention has been particularly worked out in connection with amachine for grinding. or finishing the arcuate surfaces of a cam groove.It is a comparatively simple matter to grind or finish evenly andsmoothly concentric portions of cam grooves but it is olifiicult to givean even, smooth finish to the portions of the cam groove which areeccentric to or irregularly related to the axis of rotation of the cam.

This invention has for its object to automatically adjust or regulatethe relative positions of a cam or a member having a curved surface tobe finished and the finishing member or tool, such as a grinder, in sucha manner that the walls of the cam groove or the arcuate or curvedsurfaces to be finished will be evenly and smoothly finished.

to a machine for finish- Another object of the invention is to provide.20

tool adjusting mechanism for a rotatable tool so constructed andarranged that the center of rotation' of the tool and the point ofcontact of the tool periphery with the curved or arcuate surface beingfinished will be automatically maintained on a radius of curvature ofthe surface being ground.

Further objects ofthe invention will appear from the followingspecification taken in connection with the drawings which form a part ofthis application, and in which Fig. 1 is a vertical sectional elevationof a machine constructed in accordance with the invention;

Fig. 2 is a top plan View of the machineshown f in Fig. 1, parts beingomitted for the sake of clearness;

Fig. 3 is an elevational view looking in the opposite direction fromFig. 1 and showing particularly the driving connections forreciprocating Y the tool, parts being omitted for the sake of clearness;

Fig. 4 is a vertical sectional elevation taken substantially on line 4-4of Fig. 1, looking in the direction of the arrows;

Fig. 5 is a transverse sectional plan taken substantially on line 5-5 ofFig. 4, looking in the direction of the arrows;

Fig. 6 is an elevational view taken substantially on line 66 of Fig. 1,looking in the direction of the arrows;

Fig. 7 is a vertical elevational view, partly in section, takensubstantially on line 1-1 of Fig. 1, looking in the direction of thearrows;

Fig. 8 is a sectional elevation taken through the control cams and themounting thereof;

Fig. 9 is a diagrammatic elevational view illustrating the cam tobefinished. grinding wheel, and showing the I angular adjustments of thegrinding wheel support;

Fig. 10 is a diagrammatic elevational view illustrating the cam whichcontrols the raising and lowering of the cam having a groove to beground; and

Fig. 11 is a diagrammatic elevational view illustrating the cam whichautomatically controls the oscillation of the grinding wheel.

The invention briefly described consists of a machine having a supportfor the cam having the groove to be finished, a tool support ora supportfor the grinder, and two sets of automatically operated controlmechanisms, one set being controlled in its operation by a cam which.causes the cam having the groove to be finished to be verticallyadjusted to maintain the rotatable finishing tool or grinding wheel incontact with the surface to be finished and the other set beingautomatically controlled bye. second controlcam which oscillates thetool support and, therefore, the tool, in such a manner as to alwaysmaintain the point of contact of the periphery of the grinding wheel ortool and the axis of rotation of the grinding wheel or-tool on a radiusextending from the point of contact to the center of curvature of thesurface being finished. Further details of the invention will appearfrom. the following description.

In the particular embodiment of the invention illustrated in thedrawings, the machine is mounted on a base or table 20, von one end ofwhich is mounted a vertical casing 21. In the casing 2| are mounted twovertical posts 22 and two sets of rollers, the rollers at the top of thecarriage being designated 26 and 21 and the rollers at the bottom beingdesignated 28 and 29. These rollers engage the oppositely facing insidecylindrical portions of the posts 22 and 23 and center the carriagebetween the posts.

The carriage also carries two other sets of rollers adjacent the lowerend thereof and adjacent the upper end thereof. The two sets of rollersat the lower end of the carriage are shown in the section illustrated inFig. 5, one set being indicated at 30 and 3 l and the other set beingshown at 32 and 33. The uppersets of rollers corresponding to therollers 30, 3|, 32 and 33 are mounted on the carriage in the same manneras the lower set, one pair of the upper set being shown at 35 and 36 andthe other pair being directly in back of this pair,- viewing Fig. 4, oneof the rollers of the other pair being shown at 31 in Fig. 1.

By means of the rollers above described, the carriage 25 is guided inits vertical reciprocation. The weight of the carriage and the partscarried thereby is partially counterbalanced by a weight W, shown inFig. 4; which is connected by a cable 40 around pulleys or wheels M and42 to the upper end of the carriage, as shown at 43.

The carriage 25 has laterally extending guide brackets 45 and 46, asshown in Fig. 1, in which is slidably mounted a vertical reciprocatablebar 41, this bar being supported by and pulled upwardly by springs 48and 49.

Raising and lowering control mechanism The carriage 25 is provided withbearings 50 and I in which is rotatably mounted a shaft 52 on the outerend of which is secured the cam C having a groove 53, the walls of whichare to be ground or finished. The shaft 52 has mounted thereon a wormgear 55 which meshes with a worm 56 carried by a shaft 51 mounted in asuitable bearing 58 which is connected to and carried by the carriage25. The shaft 51 has a bevel gear 60 at the lower end thereof, viewingFig. 4, and this gear meshes with a bevel gear 6I carried by a shaft 62mounted in a bearing on bracket 59 carried by and connected to carriage25. Shaft 62 is connected by a universal joint 63 and a telescopicdriving connection 34 to a shaft 65, which in turn. is connected by auniversal joint 66 to a shaft 61 which is driven by a motor M.

Through the driving connections just described, the motor drives theshaft 52 and thus rotates the cam C having the groove 53 to be finished.

The carriage 25 is controlled as to its vertical adjustment by means ofa cam I0 secured to a sleeve 1I pinned to the shaft 52 (see Fig. 8). Thecam is in turn supported on a roller 80 rotatably mounted in the upperend of a post 8| which extends upwardly through the table and bottom ofthe casing 2|. This post BI is vertically adjustable in the followingmanner. The lower end of the post is threaded into a sleeve 82 which isrotatably mounted in a bracket 83 in such a manner that the sleeve canrotate but cannot move axially. The sleeve 82 has mounted thereon a wormgear 84 which meshes with a worm 85 carried by a spindle 86, to theouter end of which is secured a dial or handle 81. By rotating the dial81 the sleeve 82 will be rotated and will adjust the post 8| vertically,thereby raising or lowering the roller 80 which supports the cam 10, andthe vertical position of the cam 10 determines the vertical position ofthe carriage and of the cam C which is carried by the shaft 52 mountedin bearings carried by the carriag 25. As the shaft 52 is rotated in themanner above described, the cam 10 will also be rotated. This cam issupported on roller 80 and since the cam is non-circular, as the camrotates the shaft 52 and work C will be raised or lowered in accordancewith the contour of cam 10.

If a single cam surface were being ground, instead of a' cam groove, thegrinding wheel could be made the same size as the follower on the control cam 10 and this cam alone could control the movement of the cam Cto be ground. However, when a cam groove is being ground, the grindingwheel must have a diameter materially smaller 4 than the width of thegroove and the axis of the grinding wheel must be angularly shifted whenthe curvature or are of the cam changes centers and radii, or thegrinding wheel will not grind the true arc.

Angular adjustment control mechanism for tool support and tool The tool,which in this instance consists of a grinding wheel carried by a shaft9|, is mounted in the manner hereinafter described in a bracket which isangularly adjusted and is, through intermediate connecting mechanism,supported on a casing 92 mounted on the table 20. The casing 92 isprovided with suitable bearings 93 for a shaft 94, on the outer end ofwhich is mounted a sprocket wheel 95 which is connected by a chain 96 toa sprocket wheel 91 carried by the upper end of the casing 92. Thesprocket wheel 91 is mounted on a shaft 98 which is connected by auniversal joint 99 and a telescopic driving connection I00 to a shaftIOI, which in turn is connected through a universal joint I02 to a shaftI03 mounted in bearings I04 formed on the carriage 25. The opposite endof the shaft I03 has secured thereto, a spur gear I06. This gear mesheswith a rack I01 formed on the vertically reciprocatable bar 41. The bar.41 has mounted thereon and extending laterally therefrom, a boss I08,on the outer end of which is mounted a roller I09. The roller I09 isheld in engagement with the periphery of the oscillating control cam 0which is mounted on the sleeve 1I carried by the shaft 52. The roller isheld in engagement with the outer periphery of the cam by means ofsprings 46 and 49. The bar 41 is provided with a longitudinal slot I I5through which the shaft 52 extends.

As the bar 41 is raised and lowered by the action of cam IIO, the rackI01 will cause the gear I06 to rotate, thus rotating the shaft I M andthrough the sprocket and gear connections described, rotating the shaft94. The axis of rotation of the shaft 94 is indicated at X on Fig. '7.

The inner end of the shaft 94 has secured thereto and extendingdownwardly therefrom, a crank arm IIG, to the lower end of which issecured a roller II1 which is guided between an arcuate guiding memberH8 and a surface II9 carried by the outer surface of the casing 92.

The crank arm II6 has secured thereto and extending laterally therefrom,a bar or supporting member I25, to the other end of which is secured avertical downwardly extending bracket or support I26 having a dovetailgroove or guideway I21 (see Fig. 2) in which is vertically adjustable, abracket I30. The bracket I30 is vertically adjusted by a thumb screw I3Iand is locked in adjusted position by a lock screw I33.

The bracket I30 slidably supports, in a manner about to be described, asleeve I31 which carries the grinding wheel shaft 9i. This sleeve issupported between sets of vertical and horizontal rollers. In Fig. 1there are shown two rollers I35 and I36 which are adjustably mounted andare positioned below the sleeve I31 in which the shaft 9I is mounted. Athird roller I38 is also adjustably mounted and engages the uppersurface of the sleeve I31 and thus the sleeve is held in verticalposition by the two lower rollers I35 and I33 and the upper roller I38.The sleeve is supported against lateral movement in a horizontal planeby two rollers I40 and HI which engage one side of the sleeve and athird roller I42 which engages the other side of the sleeve,

-points P, Z and X on .slidably mounted =thes'erollers all beingadjustably mounted in the bracket I30.

Attention is called to the fact that the axis of the shaft 9| which isindicated on Fig. 7 at Z is displaced from the axis X of rotation of theshaft 94. Due to this offset relation between the axes X and Z it willbe evident that the oscillation of the shaft 94, by reason of thevertical movement of the bar 41 controlled by the cam I II), will causethe crank arm II 6 and the bracket I30 to be oscillated, thus regulatingthe position of the grinding wheel 90 in such a manner that the point ofcontact of the grinding wheel with the surface being ground and the axisof rotation of the grinding wheel will be disposed on the radius ofcurvature of the surface being ground which is drawn from said point ofcontact to the center of curvature.

As above explained, the cam 10 controls the position of the center ofthe cam C but the point P or point of contact between the grinding wheel90 and the surface being ground and the axis Z of the grinding wheelshaft 9| do not lie on a radius about the axis Y of the cam except whenthe surface being ground lies in an are about the axis Y as a center.

Thus, as the center of curvature of the surface being ground changes,the arm IIG carrying the axis Z of the grinding wheel 90 must be swungthrough an angle in order to bring the a radius passing through the newcenter of curvature. This angle, through which the axis Z must be swung,is the angle F in Fig. 9.

In addition to a rotating movement, the shaft 35 9| and sleeve I 31 arereciprocated in the roller mounting described. The shaft is rotated inthe following manner. A cylindrical pulley I50 is mounted on the shaft9| and is driven by a belt |I from a grooved pulley I52 mounted on theshaft of a motor I53. The motor I53 is carried by a bracket I54 mountedfor vertical adjustment on the casing 92.

The sleeve I31 and shaft 9| are reciprocated in the following manner.The sleeve I31 has secured thereto and projecting laterally therefrom, aplate l55, 0n the opposite faces of which are positioned rollers I56 andI51 which are carried by a bar I58 which, as shown in Fig. 2, is

92, viewing Fig. 2. The bar I58 has secured thereto a, pin I59 which ispositioned in a slot I60 formed in the upper end of a link IBI, thelower end of which is mounted on a fixed pivot I62. Intermediate itsmounted thereon a roller I63 peripheral surface of a cam I64 mounted ona shaft I65 carried by brackets I66. The roller I63 is held in contactwith the periphery of the cam I34 by means of a spring I61.

The shaft I65 has mounted thereon a worm wheel I 10 which meshes with aworm I1I carried bya shaft I 12. shaft I12 has secured thereto a spurgear I13 which is driven by a gear I14 carried by the shaft 61. Thus thesleeve I31 and shaft 9| will be reciprocated by means of the cam I 64and link I6I.

Figs. 9, 10 and 11 illustrate diagrammatically the angular adjustment ofthe tool support when the surface of the groove in the cam 0 changesfrom an arc concentric with the axis of rotation of the cam to arcsdrawn about centers eccentric which engages the to the center ofrotation of the cam C. In Fig. 9

the roller which operates in the cam groove 53 during the use of the camis indicated at R.

on the rear face of the casing I 5 ends the link I6I has 0 The grindingwheel 90 can be used to grind the outer wall I15 of the cam groove- 53or the inner wall I16 thereof. The position of the grinding wheel 90, inorder to grind the inner 5 or outer grooved wall or surface, isdetermined by the vertical adjustment of the bracket I30.

In the particular cam groove illustrated in Fig. 9, the portion of thecam between the points A and B in an anti-clockwise direction is con- IOcentric with reference to the axis of rotation Y of the cam C having thegroove being ground. The axis Z of the grinding wheel 90, the axis X ofthe shaft 94-, and the point P of contact be tween the wheel 90 andsurface I15, are located I5 on a radius about Y as a center. However,the portion of the cam groove between the points B and D is drawn on acurve having its center at the point E. In order to maintain the pointof contact P between the grinding wheel 90- and 20 the surface beingground between the points 3 and D, the axis Z of the grinding wheelshaft 9| and the axis X of the shaft 94 on a radius drawn through thecenter E of curvature of the arc B, D, the position of the axis Z ofrotation of the grinder shaft 9| must be angularly displaced and this isaccomplished by means of the cam IIO which is so designed that the crankarm II6 will [be oscillated in a manner to maintain the point P and theaxis Z on the radius I80 drawn between the center of curvature E of thearc B-D and the point P. The angle between a radius passing through theaxis Y of the cam C and the axis X of the shaft 94 and between thecenter ofthe curvature E of the arc 3-D and the axis X, is shown at F.In other words, the angle F represents the angular ad,- J'ustmentnecessary to maintain P, Z and X on the radius I80 of the arc B, D. Itwill be noted that this angle varies from the point B to the 40 point D.Moreover, when the grinding wheel is engaging the portion of the wallI15 between the point D and the point G, the grinding operation istaking place on an arc drawn about the center H. This necessitates afurther angular adjustment of the axis Z. The portion of the surface I15between points G and A has a curvature drawn about the center I.

By means of the particular design of the cam IIO, this angularadjustment of the tool support 0 is so regulated that the grinding wheel90 will be maintained in a position in which the pointP and the point Zwill always be located on the radius I80 from the point E to the point Pwhen the surface being ground is disposed between the points B and D.When the surface disposed between the points D and G is being ground,the grinding wheel will be so adjusted that the point of contact Pbetween the grinding wheel and this portion of the surface and the axisZ of the grinding wheel will be located on a radius drawn between thecenter H and the point P. Furthermore, as hereinbefore stated, wheneverthe surface I 16 is to be ground or finished, the tool is verticallyadjusted by the vertical adjustment of the bracket I30 and the angulardisplacement of the tool support is accomplished in the same manner asthat above described.

Referring to Fig. 10, attention is called to the fact that the contourof the cam 10 follows or is the same as the curvature of the surface I16of the cam C. In Fig. 11 the cam I I0 follows the curvature of the pathof movement of the axis X of shaft 94. The cams 10 and H0 as shown arelarger than the cam surfaces of cam C in order to obtain greateraccuracy in the cam and tool adjustments.

From the foregoing specification it will be clear that by means of thetwo control cams and the mechanism operated thereby, the walls of a camgroove or any arcuate surface can be evenly and smoothly finishedregardless of the displacement of the center of curvature of the arcuatesurface from the axis of rotation of the member on which the surface isformed.

Although one specific embodiment of the invention has been particularlyshown and described it will be understood that the invention is capableof modification and that changes in the arrangement and in theconstruction of the various cooperating parts may be made withoutdeparting from the spirit or scope of the invention, as expressed in thefollowing claims.

What I claim is:

1. A machine for finishing cam grooves in a cam comprising a support forthe grooved cam to be finished, a tool support for rotatably supportinga finishing tool, a rotatable tool mounted on the tool support means forvertically adjusting the support for the cam to be finished, means forrotating said cam, and means for angularly adjusting said tool supportto maintain the point of contact between the tool and surface beingfinished and the axis of rotation of the tool on the radius of curvatureof the surface being ground.

2. A machine for finishing cam grooves in a cam comprising a support forthe grooved cam to be finished, a tool support for rotatably supportinga finishing tool, a rotatable tool mounted .on the tool supportautomatic means including a control cam for vertically adjusting thesupport for the cam to be finished, means for rotating said cam to befinished, and automatic means including a second control cam andoperative mechanism controlled by said second control cam and connectedto the tool support for angularly adjusting said tool support tomaintain the point of contact between the tool and surface beingfinished and the axis of rotation of the tool on the radius of curvatureof the surface being. ground.

3. A machine for finishing cam grooves in a cam comprising a support forthe grooved cam to be finished, a tool support for rotatably supportinga finishing tool, a rotatable tool mounted on the tool support automaticmeans including a control cam for vertically adjusting the support forthe cam to be finished, means for rotating said cam to be finished, andautomatic means including a second control cam and vertically adjustablemeans controlled thereby for angularly adjusting said tool support tomaintain the point of contact between the tool and surface beingfinished and the axis of rotation of the tool on the radius of curvatureof the surface being ground.

4. A machine for finishing cam grooves in a cam comprising a support forthe grooved cam to be finished, a tool support for rotatably supportinga finishing tool, a rotatable tool mounted on the tool support automaticmeans including a control cam for vertically adjusting the cam to c befinished, means for rotating said cam to be finished, and automaticmeans including a second control cam and vertically adjustable meanscontrolled thereby and oscillatable driving connections operated by saidvertically adjustable means for angularly adjusting said tool support tomaintain the point of contact between the tool and surface beingfinished and the axis of rotation of the tool on the radius of curvatureof the surface being ground.

5. A machine for finishing cam grooves in a cam comprising a support forthe grooved cam to be finished, a vertically adjustable tool support forrotatably supporting a finishing tool, a rotatable tool mounted on thetool support automatic means for vertically adjusting the support forthe cam to :be finished, means for rotating said cam to be finished, andautomatic means for angularly adjusting said tool support to maintainthe point of contact between the tool and surface being finished and theaxis of rotation of the tool on the radius of curvature of the surfacebeing ground.

6. A machine for finishing cam grooves in a cam comprising a support forthe grooved cam to be finished, a tool support for rotatably supportinga finishing tool, a rotatable tool mounted on the tool support means forrotating said tool, means for axially reciprocating said tool, automaticmeans for vertically adjusting the support for the cam to be finished,means for rotating said cam, and automatic means for angularly adjustingsaid tool support to maintain the point of contact between the tool andsurface being finished and the axis of rotation of the tool on theradius of curvature of the surface being ground.

7. A machine for finishing arcuate surfaces in a blank comprising meansfor supporting a blank having an arcuate surface to be finished, meansfor supporting a rotatable finishing tool, a rotatable tool mounted onsaid tool support, automatically operating means for verticallyadjusting said support for the blank, means for rotating said blank, andautomatically operating means for angularly adjusting the tool supportrelative to a radius from the point of contact between the tool andsurface being finished and the center of rotation of said blank tomaintain the point of contact of the tool and said arcuate surface ofthe blank and the axis of rotation of the tool on the radius ofcurvature of said arcuate surface.

JOHN VAN BUREN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,924,003 Shaw et al Aug. 22,1933 2,091,456 Rybick Aug. 31, 1937 2,210,273 Wildhaber Aug. 6, 19402,247,412 Rybicky July 1, 1941 2,421,548 Davies June 3, 1947

